Pump motor controller



Sept. 15, 1953 D. R. NAHMENS 2,651,996

PUMP MOTOR CONTROLLER Filed Aug. 18, 1950 2 Sheets-Sheet l 1977'0E/VEVS.

Sep 1953 D. R. NAHMENS 2,651,996

PUMP MOTOR CONTROLLER Filed Aug. 18, 1950 2 Sheets-Sheet 2 IN V EN TOR.0902M Q. 72%,

H TWO/ENE Patented Sept. 15, 1953 OFFICE PUMP MOTOR CONTROLLER Donald R.Nahmens, Milwaukee, Wis.

Application August 18, 1950, Serial No. 180,132

15 Claims. 1

This invention relates to improvements in pump motor controllers andmore particularly to motor controllers for oil tank truck pumps.

Oil tank trucks are usually provided with positive displacement geartype pumps for pumping oil from the truck tank, through a flexible hosehaving a shut-oil nozzle valve at the delivery end thereof, and intoresidence oil storage tanks or the like. These pumps are usually drivendirectly by the engine of the truck through a power take oh, the pumpingspeed of the engine being con siderably higher than the normal idlingspeed thereof. The speed of the engine is usually controlled by a handthrottle located in the truck cab.

Oil pumps of the positive displacement type are usually provided with aconventional spring loaded pressure relief bypass valve which, whenopen, provides communication between the discharge side of the pump andthe inlet side of the pump. This communication, however, is ordinarilyof considerably smaller cross sectional area than that of the outletconnection of the pump. As a result, when the engine and the pump arerun at pumping speed and the hose nozzle is closed, the bypass valvecannot accomodate all of the discharge from the pump without highpressures being built up within the pump which cause much objectionablevibration. This vibration actually shakes loose the fittings on the pumpand adjacent equipment, thereby causing leakage, and requiring frequenttightening of said fittings. of this vibration the pumping speed of theengine and of the pump must be kept lower than the pumps maximumefiicient pumping speed, in order to keep the vibration down below theactual danger point.

A number of control devices have been de veloped in an attempt to solvethe problem presented by this type of p imp vibration. Certain of thesedevices depend. upon engine vacuum for operation, and have notbeenentirely satisfactory because of the fact that engine vacuum is of sucha fluctuating nature. Certain of the previous devices also required; afluid conduit extending to the engine carburetor, as well as a vacuumline extending to the intake manifold. These conduits extended from theengine back to the meter compartment of the truck. In addition, theprior control devices are not readily adaptable to all makes of pumps.

With the above in mind it is a principal object of the present inventionto provide means for eliminating the objectionable vibration which isset up in a positive displacement pump when the 2: discharge conduitthereof is shut oil and while the motor and pump are running at pumpingspeed.

A further object of the invention is to provide an engine controllerwhich automatically slows a pump motor to idling speed when the deliverynozzle valve of said pump is closed, and which speeds the motor up topumping speed upon opening of the delivery valve.

A further object of the invention is to provide an improved pump motorcontroller of the class described which, by reason of the fact that iteliminates objectionable vibration, greatly reduces wear and permits thepump to be run at its maximum efficient speed during pumping, to therebyincrease the output of the pump and decrease pumping time.

A further object of the invention is to provide an improved pump motorcontroller of the class described, the major portion of which can bemounted under the hood of the truck or behind the dashboard thereof andwhich requires two wires only to extend from this portion of the deviceto the remainder thereof normally located in the hose reel compartment.

A more specific object of the invention is to provide an improved deviceof the class described which is responsive to the pressure on thedischarge side of the pump, said pressure actuating electrical pressureswitches which form part of an electrical control circuit with a pair ofmotor throttle actuating solenoids.

A further object of the invention is to provide an improved motorcontroller of the class described which is readily adaptable for use onall oil tank trucks regardless of the type of pumps thereon.

A further object of the invention is to provide an improved electricalmotor controller which is economical in its consumption of electricalpower.

A further object of the invention is to provide an improved controllerof the class described which is relatively simple in construction, whichis inexpensive to manufacture, easy to install, and which is otherwisewell adapted for the purposes described.

With the above and other objects in View, the invention consists of theimproved pump motor controller and all of its parts and combinations asset forth in the claims and all equivalents thereof.

In the drawings accompanying and forming a part of this specification,wherein are shown two embodiments of the invention and wherein 3 likecharacters of reference indicate the same parts in all of the views:

Fig. 1 is a semi-diagrammatic plan view of the preferred form of theimproved controller in idling position;

Fig. 2 is a view similar to Fig. 1 showing the improved controller inpumping position;

Fig. 3 is a fragmentary view taken through the improved controllerapproximately along the line 3-3 of Fig. 1.

Fig. 4 is a fragmentary longitudinal vertic sectional view of a portionof the improved controller taken approximately along the line 4-4 ofFig. 1;

Fig. 5 is a semi-diagrammatic plan view of a modified form of theinvention in idlin position;

Fig. 6 is a view similar to Fig. 5 but showing the modified controllerin pumping position;

Fig. 7 is a fragmentary rear end View of a tank truck rear end hose reelcompartment showing the door operated switch; and

Fig. 8 is a fragmentary side view on a reduced scale of the oil pumpingsystem of an oil tank truck, the outline of said truck being shown indotted lines.

Referring more particularly to Fig. 8, the numeral 83 indicates an oiltank truck having mounted thereon an oil tank 89. The truck 88 isprovided with an engine 90 having a speed con trol or throttle arm 39which may be connected to the engine carburetor. A rod 40 connects thearm 39 to the accelerator (not shown) of the truck 88 and said arm isprovided with a te sion spring I39 for urging said arm toward idlingposition. The engine 90 has a drive shaft 9| for driving a power takeoff unit 92 which may be engaged or disengaged by means of a lever 93.Mounted in a compartment 53 at the rear of the tank 89 is a hose reel 95on which is normally coiled a flexible delivery hose 96. The hose 96 isprovided at its terminus with a manual shut off nozzle valve 91. Apositive displacement pump 98 has its inlet connection 99 communicatingwith the interior of the tank 89 and has its discharge connection Icommunicating with a meter NH. The meter |'0| is connected to the hose96 through a conduit I02 and the reel 95 in the usual manner.

Referring to Fig. 1 of the drawing, the numeral I0 indicates a baseplate on which are mounted a pair of coaxial spaced solenoids II and I2.The solenoids II- and I2 are provided with plungers I3 and I4respectively which are axially and non-rotatably movable therein. Theadj cent ends of the plungers I3 and I4 are connected to opposite endsof a rectangular cam plate E5, as by bolts I6. The cam plate I is formedwith a slot I! having end portions 1 adjacent opposite side edgesthereof and extending parallel with the axis of the plungers. The endportions I8 are connected by a diagonally extending intermediate slotportion |9,, as shown.

Mounted on the base I0, adjacent the outer end of the solenoid Ii and ina position to be actuated by the outer end of the plunger I3 is anormally closed switch 29 having a pair of contacts 2| and 22. Mountedon the opposite end of the base I ii, adjacent the outer end of thesolenoid I2 and in a position to be actuated by the plunger I 4, is anormally closed electric switch 23 having a pair of contacts 24 and 25.

Bolted onto the base I0 is a transversely extending inverted channelshaped member 26- The member 26 is formed with a slot 2! extendinglongitudinally thereof along the center line of its upper wall. The slot21 is preferably Wider than the slot I'I. Slidably positioned on thebase I0 under the inverted channel member 26 is a slidable bar 28 whichis preferably rectangular in cross section, as shown. An upstandingcylindrical pin 29 is bolted to the upp surface of the slide bar 28 andextends through the slot 21 in the member 26. The pin 29 is formed witha portion 30 having a diameter substantially equal to the width of theslot 2'! and is formed with a portion of reduced diameter 3|, thediameter of which is substantially equal to the width of the slot I1.Between the portions 30 and 3| the pin 29 is provided with a shoulder32.

The portion 3| of the pin 29 extends through the slot H, as shown inFig. 3, and the cam plate I5 rests on the shoulder 32. Below theshoulder 32 the pin 29 is formed with a diametrically extending bore 33in which is positioned the end of a wire 34. The pin 29 is formed with atapped axially extending aperture 35 in which is positioned a, set screw36 for locking the wire 34 in the bore 33. The wire 34 is provided witha metallic tubular sheath 31 in which it is slidable, and a bracket 38securely positions one end of the sheath 3'! adjacent an end of theslide member 26, as shown.

The numeral 39 indicates the speed control or throttle arm on thecarburetor of the motor of the truck on which the improved controller isshown as being mounted. An accelerator rod 40 is pivotally connected tothe arm 39, and depression of the accelerator (not shown) moves the rod40 axially to thereby pivot the arm 39 in the usual manner from thesolid line idle position of Fig. 1 toward the dot and dash line fasterrunning position of Fig. 1. A block 4| may be fixed to the rod 40 and isformed with a bore 42 which is parallel with the rod 40. The wire 34extends slidably through the bore 42 and has fixed to the end thereof acollar 43. The arm 39 and the rod 40 are normally urged toward the idleposition, as shown in Fig. 1, by the spring I39.

Referring to Figs. 1, 2 and 8, the numerals 44 and 45 indicate a pair ofpressure switches, said switches communicating with a common T conduit46 which is in communication with the discharge pressure of the oil pumpand may be connected to the conduit I02 of the oil tank truck, as shownin Fig. 8. The pressure switch 44 has a pair of contacts 4! and 48 whichare closed when the pressure in the conduits 46 and I02 exceeds apredetermined value, for example pounds. The contacts 41 and 48 areopened when the pressure in the conduits 46 and I02 falls below thepredetermined pressure. The pressure switch 45 has a pair of contacts 49and 50 which are opened by pressure in conduits 46 and I02 above apredetermined value which is preferably less than the pressure settingof the switch 44, for example 40 pounds, and are closed when thepressure in said conduits falls below said predetermined value. Thepressure switches 44 and 45 are preferably adjustable so that thepressure of actuation may be varied to suit individual pumpcharacteristics.

The numeral 5| indicates a manually operated single pole single throwswitch preferably located in the cab of the truck 88. The numeral 52indicates a. normally closed push button type switch which is.preferably located in; the hose.

compartment 53 in a position to. be actuated. by

the door 55 when said. door is closed. The con:- tacts of the switch 52are opened when. the doorv 55 is in closed position, and the contacts;of

said switch are closed when the. door 55" isopened. This feature.prevents. operating of the improved controller except when the door 55is open. The numeral 56 indicates: the battery of the truck 88.

The electric circuit of the improved controller will now be described. Awire 51 connects: the

contacts are and 49 with one side ofthe switch 5!. series and areconnected to one side of the. battery 56. A. wire 58 connects thecontacts ll. and 21, and a wire 59 connects the contacts 58' and 24. Onewire 55 of the solenoid H is connected: to the contact 22, and onewireiii of the solenoid.

i2 is connected to the contact 25. The second wire 62 of the solenoid iI is connectedto the secnd wire 53 of the solenoid l2, and said wiresareconnected by a wire 64 to the other side of the battery 56.

Operation When the truck is traveling toward a delivery I point, theswitches and. 52 are both open and the parts of the device are disposed,as shown in Fig. 1, with the exception that the contacts of the switches44, 5! and 52, are open and the contacts of the switch are closed. Uponreaching the delivery site, the manually operated.

switch 5i is closed by the operator and the power take off for operatingthe pump is engaged, the engine accelerator being und'epressed so thatthe engine idles and the rod 40 and lever 39. are positioned by thespring I39 as shown in Fig. 1.v

Upon opening the door of. the hose reel compartment 53, the switch 52automatically closes. to complete the circuit to the battery 55 and.

render the controller operative. The operator then withdraws the hose 96from the hose reel compartment 53, the nozzle valve 91 being normallyshut off. During this time the engine 90 is driving the oil pump at aslow speed, and

even though the hose nozzle valve 91 is shut oif, the bypass valve ofthe pump 98 can accommodate all of the oil being pumped by the pumpwithout vibration. However, the pressure in the hose 96, andconsequently also the conduits t6 and ace, is above the predeterminedpressure necessary to close the contacts. of the switch 44', and to openthe contacts of the switch 45, as shown in Fig. 1.

At the instant the delivery nozzle valve is opened, the pressure in thehose and in the conduit 56 drops below the predetermined level of topounds, thereby opening the contacts 'of the switch i t and closing thecontacts of the switch Electrical current then flows through theswitches 52, 5!, 45 and 23 and energizes the. solenoid 62 causing theplungers l4 and It, as well as the plate Hi, to be moved. toward theright, as viewed in Fig. 1, to the position of Fig, 2. As the plate :5moves toward the right, the pin 29 is moved transversely by the slot IT.to. its position shown in Fig. 2. The slide. bar 28, of course, moveswith the pin 29 and supports the same.

As the pin 29 so moves, it pulls with it the wire it, thereby causingthe collar 43', fixed to the The switches 5i. and 5.2 are connected in.

opposite-endof theewire 34, toengage-the block tion. the engine isspeeded up so that it drivestheoilpumpat a predetermined-speed: which ispreferablyitsmaximum efficient pumping speed;

As the plungers [3' and Ill are moved toward the right, as. described,the contactsof the switch 2d return to their normally closed positionand the contacts, of the switch 23 are opened by the- Opening oftheplunger 44,, as. shown in Fig; 2. contacts-of the-switch 23 shuts offthe current to the solenoid: l2, thereby deenergizing the same andpreventing it from heating up and from drawing further electricity.

When the hose nozzle valve 91 is closed; shutting off the flow of, oilthrough the dischargehose, apressure beyond 50.pounds quickly buildsup-within the hose and the conduits 45 and I02. This'causes the contactsof the switch M to close and the contacts of the switch 55 to open,therebypermitting current to flow from the battery 56throughitheswitches 52, 51, it and 23 to energize the solenoid lil.The-energized solenoid i 5 moves the plunger it to the left, pullingwith it the plate l5 and the plunger id, to the position of Fig; 1.As'the plate l5is moved. toward the left, the slot l1. moves the pin 29transversely to its position shown in Fig. 1', thereby moving with itthe wire t' iand moving the collar 63 on the opposite end of said wireto. the right, as viewed in Figs. 1' and 2, to permit the block 41, therodv MI and the arm 39 to return totheir positions-of Fig. 1 under theurging of the spring I39. This immediately slows the engine 90andthepumpSB to idling speed. As shown in Fig. 1, the contacts of theswitch 20 areopened when the plunger i3 is moved toward: the left toidling position. This deenergizes the solenoid ll, preventing it fromheating upand from drawing any further current.

While the slot ll in the-plate i5 is operative to cause transversemovement of the pin 29 in responseto longitudinal movement of saidplate, the end portions 18 of said slot, being disposed at substantiallya right angle to the path of movementof the pin 29, prevent transversemovement of the pin 29' While said pin is positioned in said endportions. The pin 29 is, therefore, lockedin position whenever it isdisposed in an end portion [f theslot l'i'. Transmission from the blockGil to the wire 35' of any force acting to the left, as viewed in Figs.1 and 2, is prevented by the slidable engagement of the wire 34 in thebore 42. of saidblock.

I-t isthus apparent that the speed of the engine Siland of the oil pump98 is instantly adjusted by the improved controller in response topressure changes on. the discharge side of. the pump 9.8 resulting fromopening or closing of. the delivery nozzle valve 97. As a result, theoil pump 98- at all times runs without any of the objectionablevibration which normally occurs when said pump is run at pumping speed.with the discharge nozzle closed. The elimination of this vibrationgreatly reduces leakage at the fit gallonage per minute permitted by theimproved controller, a substantial amount of the operator's time issaved, due to the fact that no manual throttle adjustments need be madeby the operator from the time he leaves the cab of the truck on arrivalat the delivery site until he returns to the cab on completion of thedelivery. It is apparent, therefore, that the improved controllerprovides a double time saving feature.

A modified form of the invention, which is adapted for use on largertrucks, is shown in Figs. and 6. The numeral It indicates an L-shapedbase upon which is mounted a pair of solenoids I I and I 2 disposed inspaced relation at substantially a right angle with respect to eachother. A normally closed switch is mounted adjacent one end of thesolenoid II in a position to be actuated by the plunger I3 of saidsolenoid. A normally closed switch 23 is mounted adjacent an end of thesolenoid I2 in a position to be actuated by the plunger I4 of saidsolenoid. A pair of pressure switches 44 and 45, preferably identicalwith the pressure switches 44 and 45 of the preferred form of theinvention, are connected to a common T conduit 46 which may communicatewith the conduit I02 of the truck 88. The switches 5| and 52 areidentical with the switches 5| and 52 of the preferred form of theinvention. The wiring diagram of the modified form of the invention ispreferably identical with that of the preferred form, and the electricconductors indicated by primed numerals in Figs. 5 and 6 are identicalwith those indicated by the same numbers unprimed in Figs. 1 and 2.

Fixed to the base IB and spaced from the adjacent ends of the solenoidsII and I 2 is a bracket ID on which is pivotally mounted, for movementin a plane parallel with the base IE3, a pawl or detent "II The pawl 'IIis formed along one edge SI, at the end thereof adjacent the solenoidI2, with a notched out portion I2 forming a shoulder 13. At its oppositeend the pawl TI is formed with an apertured ear 14. The ear F4 isconnected to an ear I5 on the solenoid II by a coiled tension spring 16which normally urges the pawl II in a clockwise direction about itspivot H. The plunger I3 of the solenoid II is linked to the end portionof the pawl II adjacent the notch 12 by means of a link 18.

A second bracket I9 is mounted on the base Ill, and pivotally mounted onthe bracket I9 for movement coplaner with the pawl II is a lever 89. Thelever 83 is positioned so that one end thereof is engageable with theedge SI of the pawl II. This end of the lever 80 is linked to theadjacent end of the plunger I4 of the solenoid I2 by means of a link 82.A coil tension spring 83 connects the opposite end portion of the lever80 with an ear 64 on the solenoid l2 and normally urges the lever 80 ina counter-clockwise direction about its pivot 85. Counter-clockwisemovement of the lever 80 is limited by a set screw 86 extending througha block 81 carried by the bracket Hi.

The end of the lever 80 adjacent the spring 83 is pivotally connected toa throttle rod 34' which slidably extends through a bore 42 in a block4| in the same manner that the wire 34 extends through the bore 42 inthe block M in the preferred form of the invention. The rod 34' hasfixed thereto a collar 43, and movement is transmitted from the rod 34to the accelerator rod 48' and the throttle arm 39 in the same mannerthat movement is transmitted from the wire 34 to the arm 39 in thepreferred form.

Fig. 5 shows the parts of the modified form of the invention disposed inidle position. At the instant the delivery nozzle valve is opened, thepressure in the conduit I02 and in the delivery hose 96 drops below 40pounds, causing the switch 44 to open and the switch 45 to close.Current then flows from the battery 56 through the switches 52, 5|, 45'and 23 to energize the solenoid I2, which in turn pulls the plunger I4to the right to the position thereof shown in Fig. 6. This movement ofthe plunger I4 pivots the lever in a counter-clockwise direction againstthe tension of the spring 83 and moves the throttle rod 34 to the leftthereby causing the throttle arm 39 to be swung to the left to pumpingposition shown in Fig. 2. The truck engine is thereby speeded up topumping speed. As the lever 80 moves in the clockwise direction, thepawl II is pivoted in a clockwise direction by the tension spring 76 tothereby move the shoulder 73 and the notch I2 into engagement with theend of the lever 80, as shown in Fig. 6, thereby locking said lever inthis position. Simultaneously with the pivoting of the pawl H, theplunger I3 of the solenoid I I is moved toward said pawl and away fromthe switch 26', permitting the contacts of said switch to close. As theplunger 54 of the solenoid I2 is moved to the right by the energizationof said solenoid, said plunger opens the contacts of the switch 23,thereby deenergizing the solenoid I2 to prevent it from heating up andfrom drawing further electricity.

When the delivery nozzle valve is closed, the pressure in the hose andin the conduits 46 and I02 builds up beyond 50 pounds, to thereby causethe switch 44 to close and the switch 45 to open. This energizes thesolenoid I I by causing current to flow from the battery 56 through theswitches 52, 5|, 44 and 20. Energization of the solenoid I I causes theplunger I3 thereof to be retracted and to rotate the pawl II in acounter-clockwise direction against the tension of the spring I6. Thisrotation of the pawl TI releases the lever 80 which, under the urging ofthe tension spring 83, snaps back to the position thereof shown in Fig.5 in engagement with the edge 8| of the pawl I I. As the lever 80 is sopivoted, the plunger I4 is moved therewith to permit the contacts or"the switch 23 to close. Retraction of the plunger I3 opens the contactsof the switch 20, as shown, and deenergizes the solenoid II to therebypre vent it from heating up and from drawing further current. As thelever 80 pivots in a counterclockwise direction, the accelerator rod 40and the throttle arm 39' are permitted to return to idle position underthe urging of the spring I39. This slows down the engine 90 and the pump98 to idling speed, and the parts of the improved controller will remainas shown in Fig. 1 until the discharge nozzle 91 is again opened, atwhich time the improved controller will again automatically speed up thetruck engine 99 and the pump 98 to pumping speed.

Various changes and modifications may be made without departing from thespirit of the invention, and all of such changes are contemplated as maycome within the scope of the claims.

What I claim is:

1. In combination: a fluid pump having a discharge line provided with anormally closed shutoff valve, said discharge line normally containingfluid under pressure when said pump is opcrating; a motor drivinglyconnected to said pump and having a speedcontrol lever normally inidling position, said lever being movable between idling and pumpingpositions; a source of electrical current; a solenoid connected to saidspeed control lever in a manner to move said lever to pumping positionwhen said solenoid is energized; a first .pressure switch connected tosaid source of current and to said solenoid and responsive toapredetermined pressure in said discharge line to cause energization ofsaid solenoid and movement .of the speed control lever to pumpingposition; mechanism actuated by a second solenoid connected to saidsource of current for moving said speed control lever to idling positionwhen said second solenoid is energized; and a second pressure switchresponsive to a predetermined higher pressure in said discharge line tocause energization of said second solenoid and movement of the speedcontrol lever .to idling position.

.2. In combination: a fluid.pumphavingadis chargeline provided withalnormally closedshutofi valve, said discharge line normally containingfluid under pressure when said pump is operating; a motor drivinglyconnected to saidpump and having a speed control lever normally inidling position, said lever being movable between idling and pumpingpositions; a source-of electrical current; a solenoid connected to saidspeed control lever in a manner to move said lever to pumping positionwhen said solenoid is energized; a first pressure switch connected tosaid source of current and to said solenoid and responsiveto apredetermined pressure in said discharge line to cause energization ofsaid solenoid and movement of the speed control leverto pumpingposition; mechanism actuated by a second solenoid connected to saidsource of current for moving said speed control lever to idling positionwhen said second solenoid is energized; a second pressure switch.responsive to a predetermined higher pressure in said discharge line tocause energization of said second solenoidand movement of the speedcontrol .leverlto idling position; a third switch responsive to movementof the control lever to pumping position for stopping the flow-ofcurrent to the first solenoid; and a fourth switch responsive tomovement of the control lever to idling position for stopping the flowof current to the second solenoid.

3. In combination: a fluid pump having a discharge lineprovided with anormally closed shutoff valve, saiddisc'harge line normally containingfluid under pressure when said pump is operat ing; a motor drivinglyconnected to said pump and having a speed control lever normally inidling position, said lever being movable'between idling and pumpingpositions; a source of electrical current; a solenoid connected tosaidspeed control lever in a manner to move said lever to pumpingposition when said solenoid is energized; a first pressure switchconnected 'to said source of current and to said solenoid and responsiveto a predetermined pressure in said discharge line to cause energizationof said solenoid and movement of the speed control lever to pumpingposition; mechanism actuated by'a second solenoid connected to saidsource of current for moving said speed control lever to idling positionwhen said second solenoid is-energized; a second pressure switchresponsive to-a predetermined higher pressure in said discharge linetocause energization of said second solenoid and movement of the speedcontrol lever to idling position; a third switch responsive to movementof the control lever to pumping position for stopping the flow ofcurrent to the first solenoid; a fourth switch responsive to movement ofthe control lever to idling position for stopping the flow or" currentto the second solenoid; and releasable means for holding said speedcontrol lever in pumping position after said first solenoid ideenergized.

4. In combination: a fluid pump having a discharge line provided with anormally closed shutoif valve, said discharge line normally contain-:ing 'iluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a speed control member movable betweenidling pumping positions, said member being normally in idling position;a source of electric current; a first electric power means connected tosaid speed control member in a manner to move the latter to pumpingposition when said power means is energized; a second electric powermeans; mechanism including said second electric power means for movingsaid speed control member to idling position when said second powermeans is energized; and pressure responsive switch :mean connected tosaid source and'to said first and second electric power means forproviding alternative electrical con- .nection of said source witheither said first or second power means, said switch means beingresponsive to a predetermined pressure in the discharge line to connectsaid source with the first power means to energize the latter and movethe speed control member to pumping position, and said switch means alsobeing responsive to a predetermined higher pressure in the dischargeline to alternatively connect said source with the second power means toenergize said second power :means and move the speed control member toidling position.

5. In combination: a fluid pump having a discharge line provided with anormally closed shutoii' valve, said discharge line normally containingfluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a speed control member movable betweenidling and pumping positions, said member being normally in idlingposition; a source of electric current; .a first solenoid connected tosaid speed controlmember in a manner to move the latter to pumpingposition when said solenoid is energized; a second solenoid; mechanismincluding said second solenoid for moving said speed control member toidling position when said second solenoid is energized; and pressureresponsive switch means connected to said source and to said first andsecond solenoids for providing alternative electrical connection of saidsource with either said first or second solenoids, said switch meansbeing responsive to a predetermined pressure in the discharge line toconnect said source with the first solenoid to energize the latter andmove the speed control member to pumping position, and said switch meansalso being responsive to .a predetermined higher pressure in thedischarge line to alternatively connect said source with the secondsolenoid to energize said second solenoid and move the speed controlmember to idling position.

6. In combination: a fluid pump having a discharge line provided with anormally closed shutoff valve, said discharge line normally containingfluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a speed control member movable betweenidling and pumping positions, said member being normally in idlingposition; a source of electric current; a first electric power meansconnected to said speed control member in a manner to move the latter topumping position when said power means is energized; a second electricpower means; mechanism including said second electric power means formoving said speed control member to idling position when said secondpower means is energized; pressure responsive switch means connected tosaid source and to said first and second electric power means forproviding alternative electrical connection of said source with eithersaid first or second power means, said switch means being responsive toa predetermined pressure in the discharge line to connect said sourcewith the first power means to energize the latter and move the speedcontrol member to pumping position, and said switch means also beingresponsive to a predetermined higher pressure in the discharge line toconnect said source with the second power means to energize said secondpower means and move the speed control member to idling position; aswitch responsive to movement of the control member to pumping positionfor stopping the flow of current to the first electric power means; anda second switch responsive to movement of the control member to idlingposition for stopping the flow of current to the second electric powermeans.

'7. In combination: a fluid pump having a discharge line provided with anormally closed shutoff valve, said discharge line normally containingfluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a speed control membermovable betweenidling and pumping positions, said member being normally in idlingposition; a source of electric current; a first solenoid connected tosaid speed control member in a manner to move the latter to pumpingposition when said solenoid is energized; a second said second solenoidfor moving said speed control member to idling position when said secondsolenoid is energized; pressure responsive switch means connected tosaid source and to said first and second solenoids for providingalternative electrical connection of said source with either said firstor second solenoids, said switch means being responsive to apredetermined pressure in the discharge line to connect said source withthe first solenoid to energize the latter and move the speed controlmember to pumping position, and said switch means also being responsiveto a predetermined higher pressure in the discharge line toalternatively connect said source with the second solenoid to energizesaid second solenoid and move the speed control member to idlingposition; a switch responsive to movement of the control member topumping position for stopping the flow of current to the first solenoid;and a second switch responsive to movement of the control member toidling position for stopping the flow of current to the second solenoid.

8. In combination: a fluid pump having a discharge line provided with anormally closed shutoff valve, said discharge line normally containingfluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a speed control member movable betweenidling and pumping positions, said member being normally in idlingposition; a source of electric current; a first solenoid connected tosaid speed control member in a manner to move the latter to pumpingposition when said solenoid is energized; a second solenoid connected tosaid speed solenoid; mechanism including control member in a manner tomove the latter to idling position when said second solenoid isenergized; and pressure responsive switch means connected to said sourceand to said first and second solenoids for providing alternativeelectrical connection of said source with either said first or secondsolenoids, said switch means being responsive to a predeterminedpressure in the discharge line to connect said source with the firstsolenoid to energize the latter and move the speed control member topumping position, and said switch means also being responsive to apredetermined higher pressure in the discharge line to alternativelyconnect said source with the second solenoid to energize said secondsolenoid and move the speed control member to idling position.

9. In combination: a fluid pump having a discharge line provided with anormally closed shutoff Valve, said discharge line normally containingfluid under pressure when said pLunp is operated; a motor drivinglyconnected to said pump and having a speed control member movable betweenidling and pumping positions, said member being normally in idlingposition; a movable cam; a cam follower connected to said speed controlmember in a manner to move the latter between idling and runningpositions in response to movement of said cam; a first solenoidconnected to said cam in a manner to move the latter in a direction tocause movement of the speed control member toward pumping position uponenergizetion of said solenoid; a second solenoid connected to said camin a manner to move the latter in a direction to cause movement of thespeed control member toward idling position upon energization of saidsecond solenoid; a source of electric current; and pressure responsiveswitch means connected to said source and to said first and secondsolenoids for providing alternative electrical connection of said sourcewith either said first or second solenoid, said switch means beingresponsive to a predetermined pressure in the discharge line to connectsaid source with the first solenoid to energize the latter and move thespeed control member to pumping position, and said switch means alsobeing responsive to a predetermined higher pressure in the dischargeline to alternatively connect said source with the second solenoid toenergize said second solenoid and move the speed control member toidling position.

10. In combination: a fluid pump having a discharge line provided with anormally closed shutoff valve, said discharge line normally containingfluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a speed control member movable betweenidling and pumping positions, said member being normally in idlingposition; a movable cam plate formed with a diagonally extending camslot; a cam follower positioned in said slot and movable transversely inresponse to longitudinal movement of said plate, said follower beingconnected to said speed control member in a manner to move the latterbetween idling and running positions in response to longitudinalmovement of said cam plate; a first solenoid connected to said cam in amanner to move the latter in one longitudinal direction to causemovement of the speed control member toward pumping position uponenergization of said solenoid; a second solenoid connected to said camin a manner to move the latter in the opposite longitudinal direction tocause movement of the speed control member toward idling position uponenergization of said second solenoid; a source of electric current; andpressure responsive switch means connected to said source and to saidfirst and second solenoids for providing alternative electricalconnection of said source with either said first or second solenoid,said switch means being responsive to a predetermined pressure in thedischarge line to connect said source with the first solenoid toenergize the latter and move the speed control memher to pumpingposition, and said switch means formed with a cam slot havingsubstantially parallel longitudinally extending end portions and adiagonal intermediate portion; a cam follower positioned in said slotand movable transversely in response to longitudinal movement of saidplate, said follower being connected to said speed control member in amanner to move the latter between idling and running positions inresponse to longitudinal movement of said cam plate, the longitudinallyextending end portions of said cam plate slot preventing transversemovement of said follower when said follower is positioned in either ofsaid end portions; a first solenoid connected to said cam in a manner tomove the latter in one longitudinal direction to cause movement of thespeed contro1 member toward pumping position upon energization of saidsolenoid; a second solenoid connected to said cam in a manner to movethe latter in the opposite longitudinal direction to cause movement ofthe speed control member toward idling position upon energization ofsaid second solenoid; a source of electric current; and pressureresponsive switch means connected to said source and to said first andsecond solenoids for providing alternative electrical connection of saidsource with either said first or second solenoids, said switch meansbeing responsive to a predetermined pressure in the discharge line toconnect said source with the first solenoid to energize the latter andmove the speed control mernher to pumping position, and said switchmeans also being responsive to a predetermined higher pressure in thedischarge line to alternatively connect said source with the secondsolenoid to energize said second solenoid and move the speed controlmember to idling position.

12. In combination: a fluid pump having a discharge line provided with anormally closed shutoff valve, said discharge line normally containingfluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a speed control member movable betweenidling and pumping positions, said member being normally in idlingposition; a lever connected to said speed control member and movabletherewith between idling and pumping positions; a source of electriccurrent; a first solenoid connected to said lever in a manner to movethe latter to pumping position upon energization of said solenoid;movable detent means engageable with Iii said lever upo'n movement ofsaid lever to pumping position to hold said lever and hence the speedcontrol member, in pumping position; a second solenoid connected to saiddetent means in a manner to release said detent means and permitmovement of said lever and speed control member to idling position uponenergization of said second solenoid; and pressure responsive switchmeans connected to said source and to said first and second solenoidsfor providing alternative electrical connection of said source witheither said first or second solenoids, said switch means beingresponsive to a predetermined pressure in the discharge line to connectthe source with the first solenoid to energize the latter and move thespeed control member to pumping position, and said switch means alsobeing responsive to a predetermined higher pressure in the dischargeline to alternatively connect said source with the second solenoid toenergize said second solenoid and permit movement of the lever and speedcontrol member to idling position.

13. In combination: a fluid pump having a discharge line provided with anormally closed shutoff valve, said discharge line normally containingfluid under pressure when said pump is operated; 3, motor drivinglconnected to said pump and having a speed control member movable betweenidling pumping positions, said member being normally in idling position;a lever connected to said control member and movable therewith between gand pumping positions and being spring u ged toward idling position; asource of electric current; a first solenoid connee ed to said lever ina manner to move the latter to pumping position upon energization ofsolenoid; a spring loaded detent mounted for engagement with said leverupon movement of said lever to pumping position to hold said lever, andhence the speed control member, in pumping position; a second solenoidconnected to said detent in a manner to release said detent and permitmovement of said lever and speed control member to idling position uponenergization of said second solenoid; and pressure responsive switchmeans connected to said source and to said first and second solenoidsfor providing alternative electrical connection of said source witheither said first or second solenoids, said switch means beingresponsive to a predetermined pressure in the discharge line to connectthe source "ith the first solenoid to energize the latter and move thespeed control member to pumping position, and said switch means alsobeing responsive to a predetermined higher pressure in the dischargeline to alternatively connect said source with the second solenoid toenergize said second solenoid and permit movement of the lever and speedcontrol member to idling position.

14. In combination: a fluid pump having a discharge line provided with anormally closed shutofi valve, said discharge line normally containingfluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a speed control member movable betweenidling and pumping positions, said member being normally in idlingposition; a source of electric current; a first electric power meansconnected to said speed control member in a manner to move the latter topumping position when said power means is energized; a second electricpower means; mechanism including said second electric power means formoving said speed control memher to idling position when said secondpower means is energized; pressure responsive switch means connected tosaid source and to said first and second electric power means forproviding alternative electrical connection of said source,

with either said first or second power means, said switch means beingresponsive to a predetermined pressure in the discharge line to connectsaid source with the first power means to energize the latter and movethe speed control member to pumping position, and said switch means alsobeing responsive to a predetermined higher pressure in the dischargeline to alternatively connect said source with the second power means toenergize said second power means and move the speed control member toidling position; and a normally closed shut-off switch in the linebetween said source and said pressure responsive switch means forpreventing the flow of current to said switch means and to said firstand second power means when said switch is opened.

15. In combination: a fluid pump having a discharge line provided with anormally closed shutoiT valve, said discharge line normally containingfluid under pressure when said pump is operated; a motor drivinglyconnected to said pump and having a. speed control member movablebetween idling and pumping positions, said member being normally inidling position; a source of electric current; a first electric powermeans connected to said speed control member in a manner to move thelatter to pumping position when said power means is energized; a secondelectric power means; mechanism including said second electric powermeans for moving said speed control mem- 16 her to idling position whensaid second power means is energized; pressure responsive switch meansconnected to said source and to said first and second electric powermeans'for providing alternative electrical connection of said sourcewith either said first or second power means, said switch means beingresponsive to a predetermined pressure in the discharge line to connectsaid source with the first power means to energize the latter and movethe speed control member to pumping position, and said switch means alsobeing responsive to a predetermined higher pressure in the dischargeline to alternatively connect said source with the second power means toenergize said second power means and move the speed control member toidling position; and a dooroperated normally closed shut-off switch inthe line between said source and said pressure respon sive switch meansfor preventing the flow of current to said switch means and to saidfirst and second power means when said switch is opened.

DONALD R. NAHMENS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 725,386 Whitney Apr. 14, 1903 947,43? Ellis Jan. 25, 19102,099,001 Peterson July 23, 1935 2,023,418 Gustafson Dec. 10, 19352,224,295 Hofer Dec. 10, 1940 2,373,143 Samiran Apr. 10, 1945

